Problem: Khan.scratchpad.disable(); For every level Kevin completes in his favorite game, he earns $370$ points. Kevin already has $380$ points in the game and wants to end up with at least $3530$ points before he goes to bed. What is the minimum number of complete levels that Kevin needs to complete to reach his goal?
Answer: To solve this, let's set up an expression to show how many points Kevin will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Kevin wants to have at least $3530$ points before going to bed, we can set up an inequality. Number of points $\geq 3530$ Levels completed $\times$ Points per level $+$ Starting points $\geq 3530$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 370 + 380 \geq 3530$ $ x \cdot 370 \geq 3530 - 380 $ $ x \cdot 370 \geq 3150 $ $x \geq \dfrac{3150}{370} \approx 8.51$ Since Kevin won't get points unless he completes the entire level, we round $8.51$ up to $9$ Kevin must complete at least 9 levels.